Steam-generator.



H. RITGHIE.

STEAM GENERATOR.

APPLICATION FILED MAY 6,1907.

922,81 7'. Patented May 25, 1909. Fi 1 2 SHEETS-BHEET 1.

Eg. I e F L I n l WITNESSES:

- /NI/ENTo/e.

JA TTORNEY.

H. RITCHIE. Y

STEAM GENERATOR. ArPLmMION FILED MAY a, 1907.

922,817. Patented May 25,1909.

H'. 0. IH2 D4 WITNESSES: NVENTOR.

lUNlTElD? TATES PATENT Flldlllllll.

HARVEY RITOHIE, OF LUDLOW, KENTUCKY, ASSIGNOR OF ONE-HALF TO ERNST BOELZNER, OF NEWPORT, KENTUCKY.

S'IEAMeG'ENER/ATOR.

T 0 all whom tt may concern.'

Be it known that l, HARVEY Rrrcnrn, a citizen o'l" the United States, and a resident ol the city ol' Ludlow, in the county of Kenton and State ol Kentucky, have invented certain new and uselul improvements in Steam-Generators, ol' which the following is a speciiication.

The several 'features ol' my invention and the various advantages lesulting 'from their use conjointly or otherwise will be apparent from the -following description and claims.

ln the accompanying drawings making a part oi this specication,-Figure 1 is a view ol a steam generator illustrating my inventiem-parts of the structure being shown in elevation and parts in section. The section is a vertical central one of the said generator. Fig. 2 is a top view oi this steam generator below the dotted section line 2, 2, of Fig. 1.

One ol' the several divisions which carries certain tubes for generating steam is here shown with the tubes. Fig. 3 is a top view ol' the generator partly in solid plan and partly in section plan. The view shows the top header" with connections to shell, also drybox lor steam take oil. Fig. l is a hall' plan view, showing three ol the top and three o'll the bottom manifolds or arms, without the tubes. Fig. 5 is a vertical central section oi' the central portion of the upper end part of the generator, and illustrating how the dry box, that is the receptacle for the dry steam may be made in a separate piece 'from the part below which conveys the i trated 1n lligs. 1, 2, 5 and 6, and the said. consteam from the central steam generating apn paratus to the outer peripheral chamber'. Fig. 6 is a horizontal section taken in the plane ol' the dotted line 6, 6, of Fig. 5. Fig. 7 is a bottom view, showing one division oi the several divisions ol' tubes present in the generator. This iigure also shows a lower pipe i'or supplying water to the central vertical tube and the connection between the same. Fig. 8 represents a vertical central section oi one ol' the manifolds or arms, and oi the connections between the manifolds, and also shows another oil said connections in elevation. Fig. 9 is a view partly in ele vation and partly in section, illustrating a modification oll the construction o'll the central tube located between the upper and lower parts of the generator. Fig. 1() is a plan view of that part ol' the lowerportion of Fig. 9 below the plane ol the dotted line 10, 10 oil Fig. 9.

Specification of Letters Patent.

Application filed May 6, 1907.

Patented May 25, 1909.

Serial No. 372,217.

Eig. 11 is a vertical central section oll the device shown in Eig. 10, said section being taken in the plane ol' the dotted line 1l, Il vl ol Eig. 10. Fig. 12 is a view partly in. elevation and partly in section, illustrating another modilication oll the central pipes (tubes) located between the upper and lower parts of the generator. E ig. 13 is a plan view ol' that p art olI the device shown in Fig. 10 which is below the plane ol the dotted line 13, 13 ol Fig. 12. Eig. 14 is a vertical central section of the device shown in Fig. 1 3, said section being taken in the plane ol' the dotted line 14, 14, ol' Fig. 13.

l will now proceed to describe my invention in detail.

The outer side portion ol the generator consists oi a shell A. l/Vithin the space inclosed by this shell A is a second shell B, not `far distant from the first. By these two shells A and B is formed a space C which from the bottom and as tar up as the level C2 per- `forms the function ol a chamber 'l'or holding water. Where the boiler is cylindrical, as it preferably is, this water chamber C may be termed the peripheral chamber C. present referred construction, the bottom ol' this c iamber C is closed at C3, and at the top at O4.

lnclosed within the shell B are present a number of tubes which when in use contain water, and are exposed to a heat external to them, and whereby the water in them is converted into steam. The preferred construction and arrangement oll these tubes is illusstruction and arrangement are as follows:- ln the center of the space inclosed by the shell B, is a large tube D extending vertically. As this tube D when in use requires a large amount oi water to supply that which is withdrawn, a large supply tube E is provided, one end of which is connected to the lower part of this tube D, and the other end to the inner shell B, and thus a water supply passage is made between the central tube l) and the chamber O.

Suitable and convenient means ol coupling the tube E to the tube D and to the shell B are provided. ln the present illustrative instance, these couplings consist ol a cap D2 at its upper end screwed to the lower' end ol' the tube D, and ci a coupling piece E2 commonly termed a Hrunner nipple, which by screw threads connects the cap 'D2 to the tube In the lOtV E. This tube E is connected to the shell B by a screw thread E5 in a common manner. The upper end of the central tube D is connected preferably by a screw thread D3 to the lower part ol the central portion ol a device which may be termed the top-header F. This top header has horizontal radial tubes G and H. The tube G affords a passage from the central vertical tube D to the peripheral chamber C at its outer end. Located at the terminus ol`l tube G, in the said chamber C is a deilector G5, vfor directing the current of water passing up in tube D, and thence through the tubeG downward in the said chamber C. The connection between the tubular arm G2 of the header F and that remainder G3 of the tube G which extends out to the chamber C is preferably effected by a screw thread G4, as indicated. The tube H serves to connect the upper portion oll the peripheral chamber C wherein steam accumulates within the drybox (or chamber K) of the header. This drybox K receives the steam generated in the entire apparatus and delivers it to a take oil tube L. The latter delivers it 'l'or use in op erating an engine or heating a radiator', or l'or whatever other purpose it is wanted.

The outer terminal ol' the tube H namely: where it intakes steam, is provided with a deflector H5 adapted to receive steam in chamber C coming from above down into this tube H, but closed against any inrush of steam from below. The advantage ol' this construction is that il' steam were admitted from below and next to the boiling and foam- `ring area ol the chamber C, the upward and direct inrush oi' steam would carry into the tube H5 wet steam and o'lten water.

The connection between the tubular arm H2 ol the header F and that remainder H3 of the tube H which extends out to the chamber C, is preferably e'll'ected by a screw thread H4 as indicated.

The header has any desired number of the radial tubes G and H. In the present instance, I have shown three of these tubes G and three oi' the tubes H.

It is to be understood that that part D2l of the header which constitutes the upper portion of the tube D, and which connects with the radial tubes G, is separated from that part of the header which constitutes the drybox K and with which the tubes H respectively connect by a single angulated diaphragm or partition M. But the header may be constructed in two pieces, in which case the partition M will remain substantially the same, but it will be composed of two partitions respectively marked M2 and M3, located side by side, substantially as shown in Figs. 5 and 6. In such a construction, that part D4t of the header which connects with the tubes G is separable from that part K of the header with which the tubes H connect. The advantage of such a contraction in two main parts as DL and K, of the header is that all and any expansion or contraction of the respective tubes and their respective header portions will be permissible without pushing or retracting the chamber C out of its normal position. For this reason, when the generator is cold and out of use, a small space D5 is preferably present between the part D4 and the part K of the header. JV hen the generator is heated,

the'parts of it expand, and this space D5 isV eliminated for the time being, and while the generator continues hot.

Within the shell B there is, in addition to the centraltube D, a series ol* tubes P. Below the tubes of the header F are a numberof manifold or radial tubes N, and the upper ends of the tubes P are duly' connected by coupling nuts P2 to their respective radial tubes N. Below Vand within the shell B are a series of radial manifolds or tubes i 2. The lower ends of the said series of said tubes are respectively connected by coupling nuts P2 to their respective radial tubes N2. In order to utilize the space within the shell B, l provide a number of series of said tubes P. Thus to each of the upper radial tubes N, I connect two series of such tubes P and likewise to each. of the lower radial tubes, l connect two series of four tubes P and in the other series froml the same radial tube are three tubes P. lt is understood that these two seiies of tubes P after encircling the tube N reach the lower radial tube N2 preferably located in a vertical plane beneath said tube N last named. But in encircling the tube D, these two series travel around the tube D in opposite directions. Preferably the arrangement ofl all the series of tubes Pbelongng to aiidconnected with the other upper radial tubes N and the lower radial tubes N2 is like that already described in relation to the tubes N and N2 last mentioned.

ln Fig. 1, T have at the right ofA tube D shown a radial tube N and a radial tube N2 without tubes P. The tubes P are omitted from these last named tubes N and N2 for the sake of perspicuity.

firmly supported. The outer end portions The upper radial tubes N and the lower radial tubes N2 are` of the lower radial tubes N2 are screwed into f' deilector N3. Thereby a passage from the tube N into the chamber C is effected, and the deilector causes the wet-steam passing up through the tubes P and out through the tubes N to pass downward in the chamber C.

The mode in which my generator operates is as follows: The tube E, tube D, tubes P and chamber C (the latter through a suitable inlet C5) are filled with water as far as the line C2. Fire is started within the shell B. Steam is rapidly generated., The steam in the tube D passes up and out of the radial tubes G, and downward into chamber C. The steam in the tubes P rises and passes into the adjacent radial tubes N and then goes through these tubes and out into chamber C, there being deflected downward by the deiiectors N3. The steam generated in the chamber C and the steam collecting therein from the tube D and the tubes P passes up in the chamber C and iinally iinds exit by going up over the deliectors H5 of the respective tubes H and thence down into these tubes H. Thence it passes in a comparatively dry state into the dryboX or compartment K. Here it loses the last portions of water which have been brought with it. It next issues from the dryboX K into the take-off or delivery tube or pipe L, and passes to the place or places where it is to be used.

l will now proceed to describe the modification shown in Figs. 9, l() and l1. By this modiiication, the several coiled tubes R are present and take the place of the one tube D heretofore described. The upper ends of these coiled tubes R respectively connect by appropriate coupling nuts with the chamber D4 already described. The lower ends of these coiled tubes R connect with a chamber R2, preferably having a well R3. l/Vhen this well R3 is present, the inlet water supply tube E will preferably be connected to this well R3 instead of being` connected directly to the chamber In Figs. 12 and 13, l have modified the direction of the tubes R of Fig. 9, so that they run straight vertically, and these tubes thus straightened l have indicated by the letter S.

Among the various advantages resulting from my invention may be noted the following :ncheapness and simplicity of construction. Ease by which the generator can be repaired. The screwing of the arms into the inside shell oll'ers an advantage in that this construction creates a circulation of the water in the water leg of the boiler in every direction, independent of the central tube, tubes or coil pipes which are shown by Figs. 9 and l2. Staggering the tube connections in the several arms so that the tubes are made to run in opposite directions is an advantage, as a better contact with the llames is secured. Placing the drybox or steam take-off in the center of the boiler in the manner which I show by my drawings, l

claim as a superior advantage over other tor-ms, as this secures the driest steam possible for service and also any condensation likely to form there is immediately converted into the driest of steam on account of being surrounded by the llames. By connecting the top header' (one with the siX arms) to the inside of the boiler, as shown, l consider also as an advantage in that it serves three purposes,one for supporting the central tube, tubes or coil pipes. lt also provides an outlet for the steam from the boiler to enter the dryboX and also for the steam generated in the central construction back into the boiler. By taking the steam from the drybox or steam tale-ot in the center of the boiler as l show, is to my mind an advantage over the usual form of taking the steam from the side of the boiler, as by my arrangement no water whatever is carried out of the service pipe. By connecting the tubes in the way shown an advantage is gained over the method of eX- panding them, as l have no plugs opposite my tubes to burn oli by the action of the iirc.

Another advantage which l claim is that with my construction l can carry a very low water line. The general construction of this boiler as shown is such that it is so easy to repair that it can be repaired without the aid of a skilled mechanic. This also is obviously a great advantage.

What l claim as new, and ol my invention and desire to secure by Letters Patent, is

1. In a steam generator, the combination oil concentric shells, a central series of generating tubes, upper radial tubes and lower radial tubes to which this central series ol' steam generating tubes is connected, the outer ends of the upper radial tubes eXtending into the steam space between the concentric shells and there provided with defleeting hood l'or de'llecting the wet steam downward, substantially as and l'or the purposes specified.

2. ln a steam generator, an outer peripheral chamber, a central series o'l' steam generating tubes, upper radial tubes and lower radial tubes to which this central series ol' steam generating tubes is connected, the

upper radial tubes extending into the peripheral chamber and at their ends in said chamber each provided with its deflector vlor deflecting the wet steam downward into said peripheral chamber, substantially as and 'for the purposes specilied.

3. ln a steam generator, the combination ol concentric shells, a series o'll spirally curved generating tubes located within the inner of said shells, lower radial tubes and upper radial tubes, connected respectively to the lower ends and the upper ends of these spirally curved tubes, these radial tubes extending into the peripheral space otl said concentric shells, and there each provided with a downwardly deflecting hood substantially as and for the purposes specil to this central tube and at the other end projecting into the peripheral chamber, a series iied.

4. In a steam generator, an outer peripheral chamber, a series of spirally curved generating tubes located within the inner shell of the said chamber, and upper radial tubes and lower radial tubes connected respectively to the upper ends and to the lower ends of these spirally curved tubes, these radial tubes extending into the peripheral chamber and deflectors at those ends of these radial tubes that are within the chamber, substantially as and for the purposes specified.

5. In a steam generator, an outer peripheral chamber, a large central vertical tube, a water supply pipe at its lower end, radial tubes at its upperl end connected at one end to this central tube and at the other end projecting into the peripheral chamber and each of these radial tubes provided with a hood, lsubstantially as and i'or the purposes speci- 6. In a steam generator, an outer peripheral chamber, a large central vertical tube, a

water supply pipe at its lower end, radial tubes at its upper end connected at one end to this central tube and at the other end projecting into the peripheral chamber, a delector at the end of each tube inside oi the chamber, substantially as and for the purposes specified.

7. In a steam generator, an outer peripheral chamber, a large central vertical tube, a

water supply pipe at its lower end, radial tubes at its upper end connected at one end to this central tube and at the other end pro jecting into the peripheral chamber, a series of tubes spirally arranged around this large vertical tube, upper radial tubes and lower radial tubes respectively connected to the upper and lower ends of the s airally arranged tubes, within the periphera chamber and each of these radial 4tubes provided with a hood, substantially as and l'or the purposes specified.

8. In a steam generator, an outer peripheral chamber, a large central vertical tube, a

- water supply pipe at its lower end, radial tubes at its upper end connected at one end to this central tube and at the other end projecting into the peripheral chamber, a de- 'lector at the end of each tube inside of the chamber, a series of tubes spirally arranged around this large vertical tube, upper radial tubes and lower radial tubes respectively connected to the upper and lower ends or' the spirally arranged tubes, within the peripheral chamber' and each ol' these radial tubes provided with a hood, substantially as and for the purposes specified.

9. In a steam generator, an outer peripheral chamber, a large central vertical tube, a water supply pipe at its lower end, radial tubes at its upper end connected at one end of tubes spirally arranged around this large vertical tube, upper radial tubes and lower radial tubes respectively connected to the upper and lower ends of the spirally arranged tubes, and de'l'lectors present at the ends of said radial tubes, within the peripheral cham* ber, substantially as and for the purposes speciiied.

10. In a steam generator, an outer peripheral chamber, a large central vertical tube, a water supply pipe at its lower end, radial tubes at its upper end connected at one end to this central tube and at the other end projecting 'into the peripheral chamber, a deflector at the end of each tube inside of the chamber, a series ot tubes spirally arranged around this large vertical tube, upper radial tubes and lower radial tubes respectively connected to the upper and lower ends ofthe spirally arranged tubes, and deliectors present at the ends of said radial tubes, within the peripheral chamber, substantially as and for the purposes specified.

11; In a steam generator, an outer peripheral chamber, a large central vertical tube, a water supply pipe at its lower end, radial tubes at its upper end connected at one end to this central tube and at the other end projecting into the peripheral chamber, a delector at the end of each tube inside of the chamber, a series of tubes spirally arranged around this large vertical tube, upper radial tubes and lower radial tubes respectively connected to the upper and lower ends of the spirally arranged tubes, within the peripheral chamber, the series of spirally arranged tubes crossing each other in opposite directions, substantially as and for the purposes specified. p

12. In a steam generator, an outer peripheral chamber, a large centralvertical tube, a water supply pipe at its lower end, radial tubes at its upper end connected'at one end tothis central tube and at the other end projecting into the'peripheral chamber, a series of tubes spirally arranged around this large vertical tube, upper radial tubes and lower radial tubes respectively connected to the upper and lower ends of the spirally arranged tubes, and deflectors present at the ends of around this large vertical tube, upper radial tubes and lower radial tubes respectively connected to the upper and lower ends of the spirally arranged tubes, and deflectors present at the ends of said radial tubes, within the peripheral chamber, the series of spirally arranged tubes crossing each other in oppesite directions, substantiallyv7 as and for the purposes speciiied.

14. ln a steam generator, a peripheral chamber, a central steam generating device or system provided below with a water supply inlet, a chamber for receiving the steam from said central device, radial tubes connected at one end with this chamber and at their other end with the peripheral chamber, a steam dryboX, radial tubes connecting the dryboX and the chamber, the said upper chamber of the central steam generating device interfitting with the dryboX, and the radial tubes of the central steam generating device occupying half of the circular space, and the radial tubes of the dryboX occupying the other half of the circular space, substantially as and for the purposes speciiied.

15. In a steam generator, a peripheral chamber, a central steam generating device or system provided below with a water supply inlet, a chamber for receiving the steam trom said central device, radial tubes connected at one end with this chamber and at their other end with the peripheral chamber, a steam dryboX, radial tubes connecting the dryboX and the chamber and a deector at the end of each of these last named tubes for compelling the steam for the drybox to rise above the deflector before entering the dryboX, the said upper chamber of the central steam generating device interlitting with the dryboX, and the radial tubes of the central steam generating device occupying the half of the circular space, and the radial tubes of the dryboX occupying the other half of the circular space, substantially as and forthe purposes speci'lied.

16. ln a steam generator, a peripheral chamber, a central steam generating device or system provided below with a water supply inlet, a chamber for receiving the steam from said central device, radial tubes connected at oneend with this chamber and at their other end with the peripheral chamber, a steam dryboX, radial tubes connecting the drybox and the chamber, the said upper chamber of the central steam generating device interiitting with the drybox, and the radial tubes of the central steam generating device occupying the half of the circular space, and the radial tubes of the dryboX occupying the other half of the circular space, and a series of spirally arranged tubes for generating steam embracing this central steam generating device, and lower' radial tubes and upper radial tubes connecting said spirally arranged tubes with said chamber,

pubstantially as and for the purposes specied.

17. ln a steam generator, a peripheral chamber, a central steam generating device or system provided below with a water supply inlet, a chamber for receiving the steam from said central device, radial tubes counected at one end with this chamber and at their other end -with the peripheral chamber, a steam dryboX, radial tubes connecting the dryboX and the chamber, and a dellector at the end of each of these last named tubes for compelling the steam for the dryboX to rise above the de'llector before entering the dryboX, the said upper chamber of the central steam generating device interiitting with the drybox, and the radial tubes of the central steam generating device occupying the half of the circular space, and the radial tubes of the dryboX occupying the other half of the circular space, and a series of spirally arranged tubes for generating steam embracing this central steam generating device, and lower radial tubes and upper radial tubes connecting said spirally arranged tubes with said chamber, substantially as and for the purposes specified.

18. ln a steam generator, a peripheral chamber, a central steam generating device or system provided below with a water supply inlet, a chamber for receiving the steam from said central device, radial tubes connected at one end with this chamber and at their other end with the peripheral chamber, a steam dryboX, radial tubes connecting the drybox and the chamber, the said upper chamber of the central steam generating device intertting with the dryboX, and the radial tubes of the central steam generating device "occupying the half of the circular space, and the radial tubes of the dryboX occupying the other half of the circular space, and a series of spirally arranged tubes for generating steam embracing this central steam generating device, and lower radial tubes and upper radial tubes connecting said spirally arranged tubes with said chamber, the'upper of these radial tubes provided in the peripheral chamber with deflectors, substantially as and for the purposes specified.

19. ln a steam generator, a peripheral chamber, a central steam generating device or system provided below with -a water supply inlet, a chamber for receiving the steam from said central device, radial tubes coni the end of each of these last named tubes for compelling the steam for the drybozr to rise above the deflector before entering the dryboX, the said upper chamber of the central lli steam generating device interlitting with n the dryboX, and the radial tubes of the central steam generating device occupying the half of the circular space, and the radial tubes of the drybox occupying the other half of the circular space, and a series of spirally arranged tubes for generating steam embracing this central steam generating device, and lower radial tubes and upper radial tubes connecting said spirally arranged tubes with said cham'ber, the upper of these radial tubes provided in the peripheral chamber with deflectors, substantially as and for the purposes specified.

20. In va steam generator, a peripheral chamber, a central steam generating device or system provided below with a water supply inlet, a chamber for receiving the steam from said central device, radial tubes connec-ted at one end with this chamber' and at their other end with the peripheral chamber, a steam drybox, radial tubes connecting the dryboX and the chamber, the said upper chamber of the central steam generating device interiitting with the dryboX, and the radial tubes ofthe central steam generating device occupying the half of the circular space, and the radial tubes ofthe drybox occupying the other half of the circular space,

' and a series of spirally arranged tubes for generating steam embracing this central steam generating device, and lower radial tubes and upper radial tubes connecting said spirally arranged tubes with said chamber, the upper radial tubes of the steam generating series being located below the upper radial tubes of the central steam radiating device and oi the radial tubes leading to the drybox, substantially as and for the purposes specified.

21. In a steam generator, a peripheral chamber, a central steam generating device or system provided below with a water supply inlet, a chamber for receiving the steam from said central device, radial tubes connected at one end with this chamber and at their other end with the peripheral chamber, a steam dryboX, radial tubes connecting the drybox and the chamber, and a deiiector at the end of each of these last named tubes for compelling the steam for the dryboX to rise above the detlector before entering the drybox, the said upper chamber of the central steam generating device inter'htting with the dryboX, and the radial tubes of the central steam generating device occupying the half of the circular space, and the radial tubes of the dryboX occupying the other halt of the circular space, and a series of spirally arranged tubes for generating steam embracing this central steam generating device, and lower radial tubes and upper radial tubes connecting said spirally arranged tubes with said chamber, the upper radial tubes of the steam generating device being located below the upper radial tubes of the central steam radiating device and of the radial tubes leading to the drybox, substantially as and for the purposes speci'lied.

22. ln a steam generator, a peripheral chamber, a central steam generating device or system provided below with a water supply inlet, a chamber i'or receiving the steam lrom said central device, radial tubes connected at one end with this chamber and at their other end with the peripheral chamber, a steam drybox, radial tubes connecting the drybox and the chamber, the said upper cham' ber of the central steam generating device intertting with the dryboX, and the radial tubes of the central steam generating device occupying the hall' of the circular space, and the radial tubes of the drybox occupying the other half oi' the circular space, and a series of spirally arranged tubes 'for generating steam embracing this central steam generating device, and lower radial tubes and upper radial tubes connecting said spirally arranged tubes with said chamber, the upper o'll these radial tubes provided in the peripheral chamber with dei'lectors, the upper radial tubes of the steam generating series being located below the upper radial tubes of the central steam radiating device and of the radial tubes leading to the drybox, substantially as and for the purposes specified. l

23. In a steam generator, a peripheral chamber, a central steam generating device or system provided below with a water supply inlet, a chamber for receiving the steam 'from the said central device, radial tubes connected at one end with this chamber and at their other end with the peripheral chamber, a steam drybox, radial tubes connecting the dryboX and the chamber, and a deflector at the end of each of these last named tubes for compelling the steam for the drybox to rise above the deflector before enter ing the dryboX, the said upper chamber oi'V the central steam generating device interitting withthe dryboX, and the radial tubes o'll the central steam generating device occupying the halll oiA the circular space, and the radial tubes of the dryboX occupying the other hall o'll the circular space, and a series of spirally arranged tubes for generating steam embracing this central steam generating device, and lower radial tubes and upper radial tubes connecting'said spirally arranged tubes with said chamber, the upper o'l' these radial tubes provided in the peripheral chamber with deilectors, the upper radial tubes of the steam generating series being located below the upper radial tubes of the central steam radiating device and of the radiating tubes leading to the dryboX, substantially as and for the purposes specified.

24. ln a steam generator having radial arms located centrally, tubes running from these arms in opposite directions, the tube connections entering the arm on one side beng staggered relatively to those entering the ico iic

arin at the other side, substantially as and for the purposes specified.

25. In a steam-generator', a group of tubesections comprising series of lower and upper headers radially arranged around a cornrnon axis and connected. by tubes ooiled ooneentrioally in alternate right and left Vertical spiral courses around the ooinlnon axis, sub stantially as set forth.

26. In a steam-generator, a group of tubeseetions comprising series of lower and upper headers radially arranged around a coniinon axis and tubes Connected in alternation to opposite sides of the headers and coiled eoneentrieally in alternate right and left vertieal spiral courses around the ooinrnon axis, substantially as set forth.

27. In a steam-generator, a tube-section consisting of an upper and a lower header radiating from a Common axis, and tubes eonneeted in alternation to opposite sides of the headers and eoiled ooncentrioally in alternate right and left Vertical spiral courses around the eonnnon axis, substantially7 as set forth.v

2S. ln a steam-generator, a tube-section consisting of an upper and a lower header radiating from a eonnnon axis, and tubes oonneoted in alternation to opposite sides of the headers and coiled eoneentrieally in alternate right and left Vertical spiral courses on f Corresponding inclined lanesv around the eonirnon axis, substantia ly as set forth.

HARVEY RITCHIE. Attest:

JOHN E. FITZPATRIGK, K. SMITH. 

